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Alkolfat F, Abdel Galeel A, Bassiouny AR, Eldeeb H, Radwan A, Ashram YA. Patterns of Visual Task-based Functional MRI Activation in Chronic Posterior Cerebral Artery Stroke Patients. Clin Neuroradiol 2023; 33:769-781. [PMID: 36867244 PMCID: PMC10449980 DOI: 10.1007/s00062-023-01274-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 01/29/2023] [Indexed: 03/04/2023]
Abstract
PURPOSE Stroke is a principal cause of disability worldwide. In motor stroke, the tools for stratification and prognostication are plentiful. Conversely, in stroke causing mainly visual and cognitive problems, there is still no gold standard modality to use. The purpose of this study was to explore the fMRI recruitment pattern in chronic posterior cerebral artery (PCA) stroke patients and to investigate fMRI as a biomarker of disability in these patients. METHODS The study included 10 chronic PCA stroke patients and another 10 age-matched volunteer controls. The clinical presentation, cognitive state, and performance in visual perceptual skills battery (TVPS-3) were determined for both patients and control groups. Task-based fMRI scans were acquired while performing a passive visual task. Individual and group analyses of the fMRI scans as well as correlation analysis with the clinical and behavioral data were done. RESULTS At the level of behavioral assessment there was non-selective global impairment in all visual skills subtests. On visual task-based fMRI, patients recruited more brain areas than controls. These activations were present in the ipsilesional side distributed in the ipsilesional cerebellum, dorsolateral prefrontal cortex mainly Brodmann area (BA) 9, superior parietal lobule (somatosensory associative cortex, BA 7), superior temporal gyrus (BA 22), supramarginal gyrus (BA 40), and contralesional associative visual cortex (BA 19). Spearman's rank correlation was computed to assess the relationship between the TVPS scores and the numbers of fMRI neuronal clusters in each patient above the main control activations, there was a negative correlation between the two variables, r(10) = -0.85, p ≤ 0.001. CONCLUSION In chronic PCA stroke patients with residual visual impairments, the brain attempts to recruit more neighboring and distant functional areas for executing the impaired visual skill. This intense recruitment pattern in poorly recovering patients appears to be a sign of failed compensation. Consequently, fMRI has the potential for clinically relevant prognostic assessment in patients surviving PCA stroke; however, as this study included no longitudinal data, this potential should be further investigated in longitudinal imaging studies, with a larger cohort, and multiple time points.
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Affiliation(s)
- Fatma Alkolfat
- Department of Neurology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Aya Abdel Galeel
- Department of Radiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Ahmad R. Bassiouny
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Hany Eldeeb
- Department of Neurology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Ahmed Radwan
- Department of Imaging and Pathology, Translational MRI, KU Leuven, Leuven, Belgium
- Leuven Brain Institute (LBI), Department of Neurosciences, KU Leuven, Leuven, Belgium
| | - Yasmine A. Ashram
- Department of Physiology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
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Bowren M, Bruss J, Manzel K, Edwards D, Liu C, Corbetta M, Tranel D, Boes AD. Post-stroke outcomes predicted from multivariate lesion-behaviour and lesion network mapping. Brain 2022; 145:1338-1353. [PMID: 35025994 PMCID: PMC9630711 DOI: 10.1093/brain/awac010] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 09/10/2021] [Accepted: 12/16/2021] [Indexed: 11/13/2022] Open
Abstract
Clinicians and scientists alike have long sought to predict the course and severity of chronic post-stroke cognitive and motor outcomes, as the ability to do so would inform treatment and rehabilitation strategies. However, it remains difficult to make accurate predictions about chronic post-stroke outcomes due, in large part, to high inter-individual variability in recovery and a reliance on clinical heuristics rather than empirical methods. The neuroanatomical location of a stroke is a key variable associated with long-term outcomes, and because lesion location can be derived from routinely collected clinical neuroimaging data there is an opportunity to use this information to make empirically based predictions about post-stroke deficits. For example, lesion location can be compared to statistically weighted multivariate lesion-behaviour maps of neuroanatomical regions that, when damaged, are associated with specific deficits based on aggregated outcome data from large cohorts. Here, our goal was to evaluate whether we can leverage lesion-behaviour maps based on data from two large cohorts of individuals with focal brain lesions to make predictions of 12-month cognitive and motor outcomes in an independent sample of stroke patients. Further, we evaluated whether we could augment these predictions by estimating the structural and functional networks disrupted in association with each lesion-behaviour map through the use of structural and functional lesion network mapping, which use normative structural and functional connectivity data from neurologically healthy individuals to elucidate lesion-associated networks. We derived these brain network maps using the anatomical regions with the strongest association with impairment for each cognitive and motor outcome based on lesion-behaviour map results. These peak regional findings became the 'seeds' to generate networks, an approach that offers potentially greater precision compared to previously used single-lesion approaches. Next, in an independent sample, we quantified the overlap of each lesion location with the lesion-behaviour maps and structural and functional lesion network mapping and evaluated how much variance each could explain in 12-month behavioural outcomes using a latent growth curve statistical model. We found that each lesion-deficit mapping modality was able to predict a statistically significant amount of variance in cognitive and motor outcomes. Both structural and functional lesion network maps were able to predict variance in 12-month outcomes beyond lesion-behaviour mapping. Functional lesion network mapping performed best for the prediction of language deficits, and structural lesion network mapping performed best for the prediction of motor deficits. Altogether, these results support the notion that lesion location and lesion network mapping can be combined to improve the prediction of post-stroke deficits at 12-months.
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Affiliation(s)
- Mark Bowren
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Joel Bruss
- Department of Neurology, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Kenneth Manzel
- Department of Neurology, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Dylan Edwards
- Moss Rehabilitation Research Institute, Elkins Park, PA 19027, USA
- Edith Cowan University, Joondalup, WA 6027, Australia
| | - Charles Liu
- Neurorestoration Center and Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
- Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA
| | - Maurizio Corbetta
- Department of Neuroscience, Venetian Institute of Molecular Medicine and Padova Neuroscience Center, University of Padua, Padova, PD 32122, Italy
| | - Daniel Tranel
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA 52242, USA
- Department of Neurology, Carver College of Medicine, Iowa City, IA 52242, USA
| | - Aaron D Boes
- Departments of Neurology, Psychiatry, and Pediatrics, Carver College of Medicine, Iowa City, IA 52242, USA
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Li R, Mukadam N, Kiran S. Functional MRI evidence for reorganization of language networks after stroke. HANDBOOK OF CLINICAL NEUROLOGY 2022; 185:131-150. [PMID: 35078595 DOI: 10.1016/b978-0-12-823384-9.00007-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
In this chapter, we review fMRI evidence for language reorganization in individuals with poststroke aphasia. Several studies in the current literature have utilized fMRI as a tool to understand patterns of functional reorganization in poststroke aphasia. Consistent with previous models that have been proposed to explain the trajectory of language recovery, differential patterns of language processing and language recovery have been identified across individuals with poststroke aphasia in different stages of recovery. Overall, a global network breakdown typically occurs in the early stages of aphasia recovery, followed by normalization in "traditional" left hemisphere language networks. Depending on individual characteristics, right hemisphere regions and bilateral domain-general regions may be further recruited. The main takeaway of this chapter is that poststroke aphasia recovery does not depend on individual neural regions, but rather involves a complex interaction among regions in larger networks. Many of the unresolved issues and contrastive findings in the literature warrant further research with larger groups of participants and standard protocols of fMRI implementation.
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Affiliation(s)
- Ran Li
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States
| | - Nishaat Mukadam
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States
| | - Swathi Kiran
- Department of Speech, Language and Hearing Sciences, Boston University, Boston, MA, United States.
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4
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Zhang L, Shen Q, Liao H, Li J, Wang T, Zi Y, Zhou F, Song C, Mao Z, Wang M, Cai S, Tan C. Aberrant Changes in Cortical Complexity in Right-Onset Versus Left-Onset Parkinson's Disease in Early-Stage. Front Aging Neurosci 2021; 13:749606. [PMID: 34819848 PMCID: PMC8606890 DOI: 10.3389/fnagi.2021.749606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/05/2021] [Indexed: 11/17/2022] Open
Abstract
There is increasing evidence to show that motor symptom lateralization in Parkinson’s disease (PD) is linked to non-motor features, progression, and prognosis of the disease. However, few studies have reported the difference in cortical complexity between patients with left-onset of PD (LPD) and right-onset of PD (RPD). This study aimed to investigate the differences in the cortical complexity between early-stage LPD and RPD. High-resolution T1-weighted magnetic resonance images of the brain were acquired in 24 patients with LPD, 34 patients with RPD, and 37 age- and sex-matched healthy controls (HCs). Cortical complexity including gyrification index, fractal dimension (FD), and sulcal depth was analyzed using surface-based morphometry via CAT12/SPM12. Familywise error (FWE) peak-level correction at p < 0.05 was performed for significance testing. In patients with RPD, we found decreased mean FD and mean sulcal depth in the banks of the left superior temporal sulcus (STS) compared with LPD and HCs. The mean FD in the left superior temporal gyrus (STG) was decreased in RPD compared with HCs. However, in patients with LPD, we did not identify significantly abnormal cortical complex change compared with HCs. Moreover, we observed that the mean FD in STG was negatively correlated with the 17-item Hamilton Depression Scale (HAMD) among the three groups. Our findings support the specific influence of asymmetrical motor symptoms in cortical complexity in early-stage PD and reveal that the banks of left STS and left STG might play a crucial role in RPD.
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Affiliation(s)
- Lin Zhang
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Qin Shen
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Haiyan Liao
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Junli Li
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Tianyu Wang
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China.,Department of Radiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuheng Zi
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Fan Zhou
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Chendie Song
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhenni Mao
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Min Wang
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Sainan Cai
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Changlian Tan
- Department of Radiology, The Second Xiangya Hospital, Central South University, Changsha, China
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Language Tasks and the Network Control Role of the Left Inferior Frontal Gyrus. eNeuro 2021; 8:ENEURO.0382-20.2021. [PMID: 34244340 PMCID: PMC8431826 DOI: 10.1523/eneuro.0382-20.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022] Open
Abstract
Recent work has combined cognitive neuroscience and control theory to make predictions about cognitive control functions. Here, we test a link between whole-brain theories of semantics and the role of the left inferior frontal gyrus (LIFG) in controlled language performance using network control theory (NCT), a branch of systems engineering. Specifically, we examined whether two properties of node controllability, boundary and modal controllability, were linked to semantic selection and retrieval on sentence completion and verb generation tasks. We tested whether the controllability of the left IFG moderated language selection and retrieval costs and the effects of continuous θ burst stimulation (cTBS), an inhibitory form of transcranial magnetic stimulation (TMS) on behavior in 41 human subjects (25 active, 16 sham). We predicted that boundary controllability, a measure of the theoretical ability of a node to integrate and segregate brain networks, would be linked to word selection in the contextually-rich sentence completion task. In contrast, we expected that modal controllability, a measure of the theoretical ability of a node to drive the brain into specifically hard-to-reach states, would be linked to retrieval on the low-context verb generation task. Boundary controllability was linked to selection and to the ability of TMS to reduce response latencies on the sentence completion task. In contrast, modal controllability was not linked to performance on the tasks or TMS effects. Overall, our results suggest a link between the network integrating role of the LIFG and selection and the overall semantic demands of sentence completion.
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Griffis JC, Metcalf NV, Corbetta M, Shulman GL. Lesion Quantification Toolkit: A MATLAB software tool for estimating grey matter damage and white matter disconnections in patients with focal brain lesions. Neuroimage Clin 2021; 30:102639. [PMID: 33813262 PMCID: PMC8053805 DOI: 10.1016/j.nicl.2021.102639] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 12/19/2022]
Abstract
Lesion studies are an important tool for cognitive neuroscientists and neurologists. However, while brain lesion studies have traditionally aimed to localize neurological symptoms to specific anatomical loci, a growing body of evidence indicates that neurological diseases such as stroke are best conceptualized as brain network disorders. While researchers in the fields of neuroscience and neurology are therefore increasingly interested in quantifying the effects of focal brain lesions on the white matter connections that form the brain's structural connectome, few dedicated tools exist to facilitate this endeavor. Here, we present the Lesion Quantification Toolkit, a publicly available MATLAB software package for quantifying the structural impacts of focal brain lesions. The Lesion Quantification Toolkit uses atlas-based approaches to estimate parcel-level grey matter lesion loads and multiple measures of white matter disconnection severity that include tract-level disconnection measures, voxel-wise disconnection maps, and parcel-wise disconnection matrices. The toolkit also estimates lesion-induced increases in the lengths of the shortest structural paths between parcel pairs, which provide information about changes in higher-order structural network topology. We describe in detail each of the different measures produced by the toolkit, discuss their applications and considerations relevant to their use, and perform example analyses using real behavioral data collected from sub-acute stroke patients. We show that analyses performed using the different measures produced by the toolkit produce results that are highly consistent with results that have been reported in the prior literature, and we demonstrate the consistency of results obtained from analyses conducted using the different disconnection measures produced by the toolkit. We anticipate that the Lesion Quantification Toolkit will empower researchers to address research questions that would be difficult or impossible to address using traditional lesion analyses alone, and ultimately, lead to advances in our understanding of how white matter disconnections contribute to the cognitive, behavioral, and physiological consequences of focal brain lesions.
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Affiliation(s)
- Joseph C Griffis
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicholas V Metcalf
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Maurizio Corbetta
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Bioengineering, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, University of Padua, Padua, Italy; Padua Neuroscience Center, Padua, Italy
| | - Gordon L Shulman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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7
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Levy HC, Poppe A, Hiser J, Wootton BM, Hallion LS, Tolin DF, Stevens MC. An Examination of the Association Between Subjective Distress and Functional Connectivity During Discarding Decisions in Hoarding Disorder. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2021; 6:1013-1022. [PMID: 33771533 DOI: 10.1016/j.bpsc.2020.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/17/2020] [Accepted: 12/23/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Individuals with hoarding disorder (HD) demonstrate exaggerated subjective distress and hyperactivation of cingulate and insular cortex regions when discarding personal possessions. No prior study has sought to determine whether this subjective distress is associated with specific profiles of abnormal brain function in individuals with HD. METHODS We used multimodal canonical correlation analysis plus joint independent component analysis to test whether five hoarding-relevant domains of subjective distress when deciding to discard possessions (anxiety, sadness, monetary value, importance, and sentimental attachment) are associated with functional magnetic resonance imaging-measured whole-brain functional connectivity in 72 participants with HD and 44 healthy controls. RESULTS Three extracted components differed between HD participants and healthy control subjects. Each of these components depicted an abnormal profile of functional connectivity in HD participants relative to control subjects during discarding decisions, and a specific distress response profile. One component pair showed a relationship between anxiety ratings during discarding decisions and connectivity among the pallidum, perirhinal ectorhinal cortex, and dorsolateral prefrontal cortex. Another component comprised sadness ratings during discarding decisions and connectivity in the pallidum, nucleus accumbens, amygdala, and dorsolateral prefrontal cortex. The third component linked HD brain connectivity in several dorsolateral prefrontal cortex regions with perceived importance ratings during discarding decisions. CONCLUSIONS The findings indicate that in patients with HD, the subjective intensity of anxiety, sadness, and perceived possession importance is related to abnormal functional connectivity in key frontal and emotional processing brain regions. The findings are discussed in terms of emerging neurobiological models of HD.
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Affiliation(s)
- Hannah C Levy
- Anxiety Disorders Center, Institute of Living, Hartford, Connecticut.
| | - Andrew Poppe
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford, Connecticut
| | - Jaryd Hiser
- Anxiety Disorders Center, Institute of Living, Hartford, Connecticut
| | - Bethany M Wootton
- Anxiety Disorders Center, Institute of Living, Hartford, Connecticut; Discipline of Clinical Psychology, Graduate School of Health, University of Technology Sydney, Sydney, South Wales, Australia
| | - Lauren S Hallion
- Anxiety Disorders Center, Institute of Living, Hartford, Connecticut; Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - David F Tolin
- Anxiety Disorders Center, Institute of Living, Hartford, Connecticut; Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut
| | - Michael C Stevens
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford, Connecticut; Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut
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Wilson SM, Schneck SM. Neuroplasticity in post-stroke aphasia: A systematic review and meta-analysis of functional imaging studies of reorganization of language processing. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2021; 2:22-82. [PMID: 33884373 PMCID: PMC8057712 DOI: 10.1162/nol_a_00025] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such that they take on new or expanded roles in language processing. We carried out a systematic review and meta-analysis of all articles published between 1995 and early 2020 that have described functional imaging studies of six or more individuals with post-stroke aphasia, and have reported analyses bearing on neuroplasticity of language processing. Each study was characterized and appraised in detail, with particular attention to three critically important methodological issues: task performance confounds, contrast validity, and correction for multiple comparisons. We identified 86 studies describing a total of 561 relevant analyses. We found that methodological limitations related to task performance confounds, contrast validity, and correction for multiple comparisons have been pervasive. Only a few claims about language processing in individuals with aphasia are strongly supported by the extant literature: first, left hemisphere language regions are less activated in individuals with aphasia than neurologically normal controls, and second, in cohorts with aphasia, activity in left hemisphere language regions, and possibly a temporal lobe region in the right hemisphere, is positively correlated with language function. There is modest, equivocal evidence for the claim that individuals with aphasia differentially recruit right hemisphere homotopic regions, but no compelling evidence for differential recruitment of additional left hemisphere regions or domain-general networks. There is modest evidence that left hemisphere language regions return to function over time, but no compelling longitudinal evidence for dynamic reorganization of the language network.
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Affiliation(s)
- Stephen M. Wilson
- Address for correspondence: Stephen M. Wilson, Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, 1215 21st Ave S, MCE 8310, Nashville, TN 37232. Phone: 615-936-5810.
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Meier EL, Sheppard SM, Goldberg EB, Head CR, Ubellacker DM, Walker A, Hillis AE. Naming errors and dysfunctional tissue metrics predict language recovery after acute left hemisphere stroke. Neuropsychologia 2020; 148:107651. [PMID: 33045231 PMCID: PMC7546715 DOI: 10.1016/j.neuropsychologia.2020.107651] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/29/2020] [Accepted: 10/02/2020] [Indexed: 12/11/2022]
Abstract
Language recovery following acute left hemisphere (LH) stroke is notoriously difficult to predict. Global language measures (e.g., overall aphasia severity) and gross lesion metrics (e.g., size) provide incomplete recovery predictions. In this study, we test the hypothesis that the types of naming errors patients produce, combined with dysfunctional brain tissue metrics, can provide additional insight into recovery following acute LH stroke. One hundred forty-eight individuals who were hospitalized with a new LH stroke completed clinical neuroimaging and assessments of naming and global language skills. A subset of participants again completed language testing at subacute, early (5-7 months post-stroke), and late (≥11 months post-stroke) chronic phases. At each time point, we coded naming errors into four types (semantic, phonological, mixed and unrelated) and determined error type totals and proportions. Dysfunctional tissue measures included the percentage of damage to language network regions and hypoperfusion in vascular territories. A higher proportion of semantic errors was associated with better acute naming, but higher proportions of other error types was related to poorer accuracy. Naming and global language skills significantly improved over time , but naming error profiles did not change. Fewer acute unrelated errors and less damage to left angular gyrus resulted in optimal naming and language recovery by the final testing time point, yet patients with more acute errors and damage to left middle temporal gyrus demonstrated the greatest increases in language over time. These results illustrate that naming error profiles, particularly unrelated errors, add power to predictions of language recovery after stroke.
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Affiliation(s)
- Erin L Meier
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Shannon M Sheppard
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Communication Sciences and Disorders, Chapman University, Irvine, CA, USA
| | - Emily B Goldberg
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Catherine R Head
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Delaney M Ubellacker
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alexandra Walker
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Argye E Hillis
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of Cognitive Science, Johns Hopkins University, Baltimore, MD, USA
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10
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Griffis JC, Metcalf NV, Corbetta M, Shulman GL. Structural Disconnections Explain Brain Network Dysfunction after Stroke. Cell Rep 2020; 28:2527-2540.e9. [PMID: 31484066 DOI: 10.1016/j.celrep.2019.07.100] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 05/29/2019] [Accepted: 07/26/2019] [Indexed: 12/29/2022] Open
Abstract
Stroke causes focal brain lesions that disrupt functional connectivity (FC), a measure of activity synchronization, throughout distributed brain networks. It is often assumed that FC disruptions reflect damage to specific cortical regions. However, an alternative explanation is that they reflect the structural disconnection (SDC) of white matter pathways. Here, we compare these explanations using data from 114 stroke patients. Across multiple analyses, we find that SDC measures outperform focal damage measures, including damage to putative critical cortical regions, for explaining FC disruptions associated with stroke. We also identify a core mode of structure-function covariation that links the severity of interhemispheric SDCs to widespread FC disruptions across patients and that correlates with deficits in multiple behavioral domains. We conclude that a lesion's impact on the structural connectome is what determines its impact on FC and that interhemispheric SDCs may play a particularly important role in mediating FC disruptions after stroke.
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Affiliation(s)
- Joseph C Griffis
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Nicholas V Metcalf
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Maurizio Corbetta
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Bioengineering, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, University of Padua, Padua, Italy; Padua Neuroscience Center, Padua, Italy
| | - Gordon L Shulman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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Stockert A, Wawrzyniak M, Klingbeil J, Wrede K, Kümmerer D, Hartwigsen G, Kaller CP, Weiller C, Saur D. Dynamics of language reorganization after left temporo-parietal and frontal stroke. Brain 2020; 143:844-861. [PMID: 32068789 DOI: 10.1093/brain/awaa023] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/25/2019] [Accepted: 12/16/2019] [Indexed: 11/13/2022] Open
Abstract
The loss and recovery of language functions are still incompletely understood. This longitudinal functional MRI study investigated the neural mechanisms underlying language recovery in patients with post-stroke aphasia putting particular emphasis on the impact of lesion site. To identify patterns of language-related activation, an auditory functional MRI sentence comprehension paradigm was administered to patients with circumscribed lesions of either left frontal (n = 17) or temporo-parietal (n = 17) cortex. Patients were examined repeatedly during the acute (≤1 week, t1), subacute (1-2 weeks, t2) and chronic phase (>6 months, t3) post-stroke; healthy age-matched control subjects (n = 17) were tested once. The separation into two patient groups with circumscribed lesions allowed for a direct comparison of the contributions of distinct lesion-dependent network components to language reorganization between both groups. We hypothesized that activation of left hemisphere spared and perilesional cortex as well as lesion-homologue cortex in the right hemisphere varies between patient groups and across time. In addition, we expected that domain-general networks serving cognitive control independently contribute to language recovery. First, we found a global network disturbance in the acute phase that is characterized by reduced functional MRI language activation including areas distant to the lesion (i.e. diaschisis) and subsequent subacute network reactivation (i.e. resolution of diaschisis). These phenomena were driven by temporo-parietal lesions. Second, we identified a lesion-independent sequential activation pattern with increased activity of perilesional cortex and bilateral domain-general networks in the subacute phase followed by reorganization of left temporal language areas in the chronic phase. Third, we observed involvement of lesion-homologue cortex only in patients with frontal but not temporo-parietal lesions. Fourth, irrespective of lesion location, language reorganization predominantly occurred in pre-existing networks showing comparable activation in healthy controls. Finally, we detected different relationships of performance and activation in language and domain-general networks demonstrating the functional relevance for language recovery. Our findings highlight that the dynamics of language reorganization clearly depend on lesion location and hence open new perspectives for neurobiologically motivated strategies of language rehabilitation, such as individually-tailored targeted application of neuro-stimulation.
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Affiliation(s)
- Anika Stockert
- Language and Aphasia Laboratory, Department of Neurology, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Max Wawrzyniak
- Language and Aphasia Laboratory, Department of Neurology, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Julian Klingbeil
- Language and Aphasia Laboratory, Department of Neurology, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Katrin Wrede
- Language and Aphasia Laboratory, Department of Neurology, University of Leipzig Medical Center, 04103 Leipzig, Germany
| | - Dorothee Kümmerer
- Department of Neurology, University of Freiburg, 79106 Freiburg, Germany
| | - Gesa Hartwigsen
- Lise Meitner Research Group, Cognition and Plasticity, Max Planck Institute of Human and Cognitive Brain Sciences, 04103 Leipzig, Germany
| | - Christoph P Kaller
- Department of Neurology, University of Freiburg, 79106 Freiburg, Germany
| | - Cornelius Weiller
- Department of Neurology, University of Freiburg, 79106 Freiburg, Germany
| | - Dorothee Saur
- Language and Aphasia Laboratory, Department of Neurology, University of Leipzig Medical Center, 04103 Leipzig, Germany
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12
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Roos NM, Piai V. Across-session consistency of context-driven language processing: A magnetoencephalography study. Eur J Neurosci 2020; 52:3457-3469. [PMID: 32432366 PMCID: PMC7586931 DOI: 10.1111/ejn.14785] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 12/28/2022]
Abstract
Changes in brain organization following damage are commonly observed, but they remain poorly understood. These changes are often studied with imaging techniques that overlook the temporal granularity at which language processes occur. By contrast, electrophysiological measures provide excellent temporal resolution. To test the suitability of magnetoencephalography (MEG) to track language‐related neuroplasticity, the present study aimed at establishing the spectro‐temporo‐spatial across‐session consistency of context‐driven picture naming in healthy individuals, using MEG in two test–retest sessions. Spectro‐temporo‐spatial test–retest consistency in a healthy population is a prerequisite for studying neuronal changes in clinical populations over time. For this purpose, 15 healthy speakers were tested with MEG while performing a context‐driven picture‐naming task at two time points. Participants read a sentence missing the final word and named a picture completing the sentence. Sentences were constrained or unconstrained toward the picture, such that participants could either retrieve the picture name through sentence context (constrained sentences), or could only name it after the picture appeared (unconstrained sentences). The context effect (constrained versus unconstrained) in picture‐naming times had a strong effect size and high across‐session consistency. The context MEG results revealed alpha–beta power decreases (10–20 Hz) in the left temporal and inferior parietal lobule that were consistent across both sessions. As robust spectro‐temporo‐spatial findings in a healthy population are required for working toward longitudinal patient studies, we conclude that using context‐driven language production and MEG is a suitable way to examine language‐related neuroplasticity after brain damage.
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Affiliation(s)
| | - Vitória Piai
- Donders Center for Cognition, Radboud University, Nijmegen, The Netherlands.,Department of Medical Psychology, Radboudumc, Donders Centre for Medical Neuroscience, Nijmegen, The Netherlands
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13
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Harnett NG, Goodman AM, Knight DC. PTSD-related neuroimaging abnormalities in brain function, structure, and biochemistry. Exp Neurol 2020; 330:113331. [PMID: 32343956 DOI: 10.1016/j.expneurol.2020.113331] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 04/06/2020] [Accepted: 04/24/2020] [Indexed: 12/20/2022]
Abstract
Although approximately 90% of the U.S. population will experience a traumatic event within their lifetime, only a fraction of those traumatized individuals will develop posttraumatic stress disorder (PTSD). In fact, approximately 7 out of 100 people in the U.S. will be afflicted by this debilitating condition, which suggests there is substantial inter-individual variability in susceptibility to PTSD. This uncertainty regarding who is susceptible to PTSD necessitates a thorough understanding of the neurobiological processes that underlie PTSD development in order to build effective predictive models for the disorder. In turn, these predictive models may lead to the development of improved diagnostic markers, early intervention techniques, and targeted treatment approaches for PTSD. Prior research has characterized a fear learning and memory network, centered on the prefrontal cortex, hippocampus, and amygdala, that plays a key role in the pathology of PTSD. Importantly, changes in the function, structure, and biochemistry of this network appear to underlie the cognitive-affective dysfunction observed in PTSD. The current review discusses prior research that has demonstrated alterations in brain function, structure, and biochemistry associated with PTSD. Further, the potential for future research to address current gaps in our understanding of the neural processes that underlie the development of PTSD is discussed. Specifically, this review emphasizes the need for multimodal neuroimaging research and investigations into the acute effects of posttraumatic stress. The present review provides a framework to move the field towards a comprehensive neurobiological model of PTSD.
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Affiliation(s)
- Nathaniel G Harnett
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Adam M Goodman
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David C Knight
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
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14
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Nair S, Szaflarski JP. Neuroimaging of memory in frontal lobe epilepsy. Epilepsy Behav 2020; 103:106857. [PMID: 31937510 DOI: 10.1016/j.yebeh.2019.106857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/04/2019] [Accepted: 12/13/2019] [Indexed: 10/25/2022]
Abstract
In a large percentage of epilepsies, seizures have focal onset. These epilepsies are associated with a wide range of behavioral and cognitive deficits sometimes limited to the functions encompassed within the ictal onset zone but, more frequently, expanding beyond it. The presence of impairments associated with neuroanatomical areas outside of the ictal onset zone suggests distal propagation of epileptic activity via brain networks and interconnected whole-brain neural circuitry. In patients with frontal lobe epilepsy (FLE), using functional magnetic resonance imaging (fMRI) to identify deficits in working, semantic, and episodic memory may provide a lens through which to understand typical and atypical network organization. A network approach to focal epilepsy is relevant in these patients because of the frequently noted early age of seizure onset. Early seizure-related disruption in healthy brain development may result in a significant brain reorganization, development of compensation-related mechanisms of dealing with function abnormalities and disruptions, and the propagation of epileptic activity from the focus to widespread brain areas (functional deficit zones). Benefits of a network approach in the study of focal epilepsy are discussed along with considerations for future neuroimaging studies of patients with FLE.
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Affiliation(s)
- Sangeeta Nair
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Neurosurgery, University of Alabama at Birmingham, Birmingham, AL, USA
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15
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Damage to the shortest structural paths between brain regions is associated with disruptions of resting-state functional connectivity after stroke. Neuroimage 2020; 210:116589. [PMID: 32007498 DOI: 10.1016/j.neuroimage.2020.116589] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/18/2019] [Accepted: 01/27/2020] [Indexed: 01/07/2023] Open
Abstract
Focal brain lesions disrupt resting-state functional connectivity, but the underlying structural mechanisms are unclear. Here, we examined the direct and indirect effects of structural disconnections on resting-state functional connectivity in a large sample of sub-acute stroke patients with heterogeneous brain lesions. We estimated the impact of each patient's lesion on the structural connectome by embedding the lesion in a diffusion MRI streamline tractography atlas constructed using data from healthy individuals. We defined direct disconnections as the loss of direct structural connections between two regions, and indirect disconnections as increases in the shortest structural path length between two regions that lack direct structural connections. We then tested the hypothesis that functional connectivity disruptions would be more severe for disconnected regions than for regions with spared connections. On average, nearly 20% of all region pairs were estimated to be either directly or indirectly disconnected by the lesions in our sample, and extensive disconnections were associated primarily with damage to deep white matter locations. Importantly, both directly and indirectly disconnected region pairs showed more severe functional connectivity disruptions than region pairs with spared direct and indirect connections, respectively, although functional connectivity disruptions tended to be most severe between region pairs that sustained direct structural disconnections. Together, these results emphasize the widespread impacts of focal brain lesions on the structural connectome and show that these impacts are reflected by disruptions of the functional connectome. Further, they indicate that in addition to direct structural disconnections, lesion-induced increases in the structural shortest path lengths between indirectly structurally connected region pairs provide information about the remote functional disruptions caused by focal brain lesions.
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16
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Versace V, Schwenker K, Langthaler PB, Golaszewski S, Sebastianelli L, Brigo F, Pucks-Faes E, Saltuari L, Nardone R. Facilitation of Auditory Comprehension After Theta Burst Stimulation of Wernicke's Area in Stroke Patients: A Pilot Study. Front Neurol 2020; 10:1319. [PMID: 31969857 PMCID: PMC6960103 DOI: 10.3389/fneur.2019.01319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/28/2019] [Indexed: 12/27/2022] Open
Abstract
Introduction: Single-pulse transcranial magnetic stimulation (TMS) and high-frequency repetitive TMS (rTMS) over Wernicke's area were found to facilitate language functions in right-handed healthy subjects. We aimed at investigating the effects of excitatory rTMS, given as intermittent theta burst stimulation (iTBS) over left Wernicke's area, on auditory comprehension in patients suffering from fluent aphasia after stroke of the left temporal lobe. Methods: We studied 13 patients with chronic fluent aphasia after an ischemic stroke involving Wernicke's area. iTBS was applied in random order to Wernicke's area, the right-hemisphere homologous of Wernicke's area, and the primary visual cortex. Auditory comprehension was blind assessed using the Token test before (T0), 5 (T1), and 40 min (T2) after a single session of iTBS. Results: At the first evaluation (T1) after iTBS on left Wernike's area, but not on the contralateral homologous area nor on the primary visual cortex, the scores on the Token test were significantly increased. No significant effects were observed at T2. Conclusion: We demonstrated that a single session of excitatory iTBS over Wernicke's area was safe and led to a transient facilitation of auditory comprehension in chronic stroke patients with lesions in the same area. Further studies are needed to establish whether TBS-induced modulation can be enhanced and transformed into longer-lasting effects by means of repeated TBS sessions and by combining TBS with speech and language therapy.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hopsital of Vipiteno-Sterzing, Vipiteno-Sterzing, Italy.,Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Kerstin Schwenker
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.,Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria
| | - Patrick B Langthaler
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria
| | - Stefan Golaszewski
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.,Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hopsital of Vipiteno-Sterzing, Vipiteno-Sterzing, Italy.,Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy.,Department of Neuroscience, Biomedicine and Movement Science, University of Verona, Verona, Italy
| | | | - Leopold Saltuari
- Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy.,Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Raffaele Nardone
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria.,Karl Landsteiner Institut für Neurorehabilitation und Raumfahrtneurologie, Salzburg, Austria.,Department of Neurology, Franz Tappeiner Hospital, Merano, Italy
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17
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Turkeltaub PE. A Taxonomy of Brain-Behavior Relationships After Stroke. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:3907-3922. [PMID: 31756155 PMCID: PMC7203524 DOI: 10.1044/2019_jslhr-l-rsnp-19-0032] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Purpose Understanding the brain basis of language and cognitive outcomes is a major goal of aphasia research. Prior studies have not often considered the many ways that brain features can relate to behavioral outcomes or the mechanisms underlying these relationships. The purpose of this review article is to provide a new framework for understanding the ways that brain features may relate to language and cognitive outcomes from stroke. Method Brain-behavior relationships that may be important for aphasia outcomes are organized into a taxonomy, including features of the lesion and features of brain tissue spared by the lesion. Features of spared brain tissue are categorized into those that change after stroke and those that do not. Features that change are further subdivided, and multiple mechanisms of brain change after stroke are discussed. Results Features of the stroke, including size, location, and white matter damage, relate to many behavioral outcomes and likely account for most of the variance in outcomes. Features of the spared brain tissue that are unchanged by stroke, such as prior ischemic disease in the white matter, contribute to outcomes. Many different neurobiological and behavioral mechanisms may drive changes in the brain after stroke in association with behavioral recovery. Changes primarily driven by neurobiology are likely to occur in brain regions with a systematic relationship to the stroke distribution. Changes primarily driven by behavior are likely to occur in brain networks related to the behavior driving the change. Conclusions Organizing the various hypothesized brain-behavior relationships according to this framework and considering the mechanisms that drive these relationships may help investigators develop specific experimental designs and more complete statistical models to explain language and cognitive abilities after stroke. Eight main recommendations for future research are provided. Presentation Video https://doi.org/10.23641/asha.10257578.
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Affiliation(s)
- Peter E Turkeltaub
- Department of Neurology, Georgetown University Medical Center, Washington, DC
- Center for Brain Plasticity and Recovery, Georgetown University Medical Center, Washington, DC
- Research Division, MedStar National Rehabilitation Hospital, Washington, DC
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18
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Wilson SM, Eriksson DK, Yen M, Demarco AT, Schneck SM, Lucanie JM. Language Mapping in Aphasia. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2019; 62:3937-3946. [PMID: 31756153 PMCID: PMC7203526 DOI: 10.1044/2019_jslhr-l-rsnp-19-0031] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Purpose Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such that they take on new or expanded roles in language processing. To make progress in characterizing the nature of this process, we need feasible, reliable, and valid methods for identifying language regions of the brain in individuals with aphasia. This article reviews 3 recent studies from our lab in which we have developed and validated several novel functional magnetic resonance imaging paradigms for language mapping in aphasia. Method In the 1st study, we investigated the reliability and validity of 4 language mapping paradigms in neurologically normal older adults. In the 2nd study, we developed a novel adaptive semantic matching paradigm and assessed its feasibility, reliability, and validity in individuals with and without aphasia. In the 3rd study, we developed and evaluated 2 additional adaptive paradigms-rhyme judgment and syllable counting-for mapping phonological encoding regions. Results We found that the adaptive semantic matching paradigm could be performed by most individuals with aphasia and yielded reliable and valid maps of core perisylvian language regions in each individual participant. The psychometric properties of this paradigm were superior to those of other commonly used paradigms such as narrative comprehension and picture naming. The adaptive rhyme judgment paradigm was capable of identifying fronto-parietal phonological encoding regions in individual participants. Conclusion Adaptive language mapping paradigms offer a promising approach for future research on the neural basis of recovery from aphasia. Presentation Video https://doi.org/10.23641/asha.10257584.
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Affiliation(s)
- Stephen M. Wilson
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Dana K. Eriksson
- Department of Speech, Language, and Hearing Sciences, University of Arizona, Tucson
| | - Melodie Yen
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
| | | | - Sarah M. Schneck
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
| | - Jillian M. Lucanie
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
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19
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Wiesen D, Sperber C, Yourganov G, Rorden C, Karnath HO. Using machine learning-based lesion behavior mapping to identify anatomical networks of cognitive dysfunction: Spatial neglect and attention. Neuroimage 2019; 201:116000. [PMID: 31295567 DOI: 10.1016/j.neuroimage.2019.07.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 07/02/2019] [Accepted: 07/04/2019] [Indexed: 12/12/2022] Open
Abstract
Previous lesion behavior studies primarily used univariate lesion behavior mapping techniques to map the anatomical basis of spatial neglect after right brain damage. These studies led to inconsistent results and lively controversies. Given these inconsistencies, the idea of a wide-spread network that might underlie spatial orientation and neglect has been pushed forward. In such case, univariate lesion behavior mapping methods might have been inherently limited in detecting the presumed network due to limited statistical power. By comparing various univariate analyses with multivariate lesion-mapping based on support vector regression, we aimed to validate the network hypothesis directly in a large sample of 203 newly recruited right brain damaged patients. If the exact same correction factors and parameter combinations (FDR correction and dTLVC for lesion size control) were used, both univariate as well as multivariate approaches uncovered the same complex network pattern underlying spatial neglect. At the cortical level, lesion location dominantly affected the temporal cortex and its borders into inferior parietal and occipital cortices. Beyond, frontal and subcortical gray matter regions as well as white matter tracts connecting these regions were affected. Our findings underline the importance of a right network in spatial exploration and attention and specifically in the emergence of the core symptoms of spatial neglect.
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Affiliation(s)
- Daniel Wiesen
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, 72076, Germany
| | - Christoph Sperber
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, 72076, Germany
| | - Grigori Yourganov
- Department of Psychology, University of South Carolina, Columbia, 29208, USA
| | - Christopher Rorden
- Department of Psychology, University of South Carolina, Columbia, 29208, USA
| | - Hans-Otto Karnath
- Center of Neurology, Division of Neuropsychology, Hertie-Institute for Clinical Brain Research, University of Tübingen, Tübingen, 72076, Germany; Department of Psychology, University of South Carolina, Columbia, 29208, USA.
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20
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Meier EL, Johnson JP, Pan Y, Kiran S. A lesion and connectivity-based hierarchical model of chronic aphasia recovery dissociates patients and healthy controls. NEUROIMAGE-CLINICAL 2019; 23:101919. [PMID: 31491828 PMCID: PMC6702239 DOI: 10.1016/j.nicl.2019.101919] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 06/05/2019] [Accepted: 06/30/2019] [Indexed: 12/28/2022]
Abstract
Traditional models of left hemisphere stroke recovery propose that reactivation of remaining ipsilesional tissue is optimal for language processing whereas reliance on contralesional right hemisphere homologues is less beneficial or possibly maladaptive in the chronic recovery stage. However, neuroimaging evidence for this proposal is mixed. This study aimed to elucidate patterns of effective connectivity in patients with chronic aphasia in light of healthy control connectivity patterns and in relation to damaged tissue within left hemisphere regions of interest and according to performance on a semantic decision task. Using fMRI and dynamic causal modeling, biologically-plausible models within four model families were created to correspond to potential neural recovery patterns, including Family A: Left-lateralized connectivity (i.e., no/minimal damage), Family B: Bilateral anterior-weighted connectivity (i.e., posterior damage), Family C: Bilateral posterior-weighted connectivity (i.e., anterior damage) and Family D: Right-lateralized connectivity (i.e., extensive damage). Controls exhibited a strong preference for left-lateralized network models (Family A) whereas patients demonstrated a split preference for Families A and C. At the level of connections, controls exhibited stronger left intrahemispheric task-modulated connections than did patients. Within the patient group, damage to left superior frontal structures resulted in greater right intrahemispheric connectivity whereas damage to left ventral structures resulted in heightened modulation of left frontal regions. Lesion metrics best predicted accuracy on the fMRI task and aphasia severity whereas left intrahemispheric connectivity predicted fMRI task reaction times. These results are discussed within the context of the hierarchical recovery model of chronic aphasia. The semantic network in neurologically-intact, healthy controls was characterized by left-lateralized connectivity. Patient connectivity was split between left-lateralized and bilateral, posterior-weighted (i.e., anterior damage) models. Controls solely recruited LITG-driven connections whereas patients recruited a distributed network of connections. Within the patient group, intra- and inter-hemispheric connections were related to lesion site and/or size. Lesion size predicted aphasia severity and fMRI task accuracy, and effective connectivity predicted task reaction times.
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Affiliation(s)
- Erin L Meier
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America.
| | - Jeffrey P Johnson
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
| | - Yue Pan
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
| | - Swathi Kiran
- Department of Speech, Language, & Hearing Sciences, Sargent College of Health and Rehabilitation Sciences, Boston University, 635 Commonwealth Avenue, Room 326, Boston, MA 02215, United States of America
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21
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Abstract
PURPOSE OF REVIEW Aphasia is often characterized in terms of subtype and severity, yet these constructs have limited explanatory power, because aphasia is inherently multifactorial both in its neural substrates and in its symptomatology. The purpose of this review is to survey current and emerging multivariate approaches to understanding aphasia. RECENT FINDINGS Techniques such as factor analysis and principal component analysis have been used to define latent underlying factors that can account for performance on batteries of speech and language tests, and for characteristics of spontaneous speech production. Multivariate lesion-symptom mapping has been shown to outperform univariate approaches to lesion-symptom mapping for identifying brain regions where damage is associated with specific speech and language deficits. It is increasingly clear that structural damage results in functional changes in wider neural networks, which mediate speech and language outcomes. Multivariate statistical approaches are essential for understanding the complex relationships between the neural substrates of aphasia, and resultant profiles of speech and language function.
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Affiliation(s)
- Stephen M Wilson
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - William D Hula
- Audiology and Speech Pathology Program, VA Pittsburgh Healthcare System, Pittsburgh, PA, USA
- Department of Communication Science and Disorders, University of Pittsburgh, Pittsburgh, PA, USA
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22
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Yi YG, Kim DY, Shim WH, Oh JY, Kim HS, Jung M. Perilesional and homotopic area activation during proverb comprehension after stroke. Brain Behav 2019; 9:e01202. [PMID: 30588768 PMCID: PMC6346665 DOI: 10.1002/brb3.1202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/22/2018] [Accepted: 11/30/2018] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION The mechanism of functional recovery in right hemisphere (RH) stroke patients when attempting to comprehend a proverb has not been identified. We previously reported that there is bilateral hemisphere involvement during proverb comprehension in the normal population. However, the underlying mechanisms of proverb comprehension following a right middle cerebral artery (MCA) infarction have not yet been fully elucidated. METHODS We here compared the brain regions activated by literal sentences and by opaque or transparent proverbs in right MCA infarction patients using functional magnetic resonance imaging (fMRI). Experimental stimuli included 18 opaque proverbs, 18 transparent proverbs, and 18 literal sentences that were presented pseudorandomly in 1 of 3 predesigned sequences. RESULTS Fifteen normal adults and 17 right MCA infarction patients participated in this study. The areas of the brain in the stroke patients involved in understanding a proverb compared with a literal sentence included the right middle frontal gyrus (MFG) and frontal pole, right anterior cingulate gyrus/paracingulate gyrus and left inferior frontal gyrus (IFG), middle temporal gyrus (MTG), precuneus, and supramarginal gyrus (SMG). When the proverbs were presented to these stroke patients in the comprehension tests, the left supramarginal, postcentral gyrus, and right paracingulate gyrus were activated for the opaque proverbs compared to the transparent proverbs. CONCLUSIONS These findings suggest that the functional recovery of language in stroke patients can be explained by perilesional activation, which is thought to arise from the regulation of the excitatory and inhibitory neurotransmitter system, and by homotopic area activation which has been characterized by decreased transcallosal inhibition and astrocyte involvement.
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Affiliation(s)
- You Gyoung Yi
- Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Dae Yul Kim
- Department of Rehabilitation Medicine, Asan Medical Center, Seoul, Korea
| | - Woo Hyun Shim
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul, Korea
| | - Joo Young Oh
- Asan Institute for Life Science, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Ho Sung Kim
- Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul, Korea
| | - Minji Jung
- Department of Rehabilitation Medicine, Asan Medical Center, Seoul, Korea
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23
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Meier EL, Johnson JP, Kiran S. Left frontotemporal effective connectivity during semantic feature judgments in patients with chronic aphasia and age-matched healthy controls. Cortex 2018; 108:173-192. [PMID: 30243049 PMCID: PMC6234086 DOI: 10.1016/j.cortex.2018.08.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 08/01/2018] [Accepted: 08/08/2018] [Indexed: 12/15/2022]
Abstract
Traditional models of neural reorganization of language skills in patients with chronic stroke-induced aphasia (PWA) propose activation of reperfused or spared left hemisphere tissue results in the most favorable language outcomes. However, these models do not fully explain variable behavioral recovery patterns observed in chronic patients. Instead, investigation of connectivity patterns of critical network nodes may elucidate better-informed recovery models. In the present study, we combined fMRI and dynamic causal modeling (DCM) to examine effective connectivity of a simple three-node left hemisphere network during a semantic feature decision task in 25 PWA and 18 age-matched neurologically intact healthy controls. The DCM model space utilized in Meier, Kapse, & Kiran (2016), which was organized according to exogenous input to one of three regions (i.e., left inferior frontal gyrus, pars triangularis [LIFGtri], left posterior middle temporal gyrus [LpMTG], or left middle frontal gyrus [LMFG]) implicated in various levels of lexical-semantic processing, was interrogated. This model space included all possible combinations of uni- and bidirectional task-modulated connections between LIFGtri, LMFG and LpMTG, resulting in 72 individual models that were partitioned into three separate families (i.e., Family #1: Input to LIFGtri, Family #2: Input to LMFG, Family #3: Input to LpMTG). Family-wise Bayesian model selection revealed Family #2: Input to LMFG best fit both patient and control data at a group level. Both groups relied heavily on LMFG's modulation of the other two model regions. By contrast, between-group differences in task-modulated coupling of LIFGtri and LpMTG were observed. Within the patient group, the strength of activity in LIFGtri and connectivity of LpMTG → LIFGtri were positively associated with lexical-semantic abilities inside and outside of the scanner, whereas greater recruitment of LpMTG was associated with poorer lexical-semantic skills.
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Affiliation(s)
- Erin L Meier
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States.
| | - Jeffrey P Johnson
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
| | - Swathi Kiran
- Sargent College of Health & Rehabilitation Sciences, Boston University, United States
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Nenert R, Allendorfer JB, Martin AM, Banks C, Vannest J, Holland SK, Hart KW, Lindsell CJ, Szaflarski JP. Longitudinal fMRI study of language recovery after a left hemispheric ischemic stroke. Restor Neurol Neurosci 2018; 36:359-385. [PMID: 29782329 DOI: 10.3233/rnn-170767] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Recovery from stroke-induced aphasia is typically protracted and involves complex functional reorganization. The relative contributions of the lesioned and non-lesioned hemispheres to this process have been examined in several cross-sectional studies but longitudinal studies involving several time-points and large numbers of subjects are scarce. OBJECTIVE The aim of this study was to address the gaps in the literature by longitudinally studying the evolution of post-stroke lateralization and localization of language-related fMRI activation in the first year after single left hemispheric ischemic stroke. METHOD Seventeen patients with stroke-induced aphasia were enrolled to undergo detailed behavioral testing and fMRI at 2, 6, 12, 26, and 52 weeks post-stroke. Matched for age, handedness and sex participants were also enrolled to visualize canonical language regions. RESULTS Behavioral results showed improvements over time for all but one of the behavioral scores (Semantic Fluency Test). FMRI results showed that the left temporal area participates in compensation for language deficits in the first year after stroke, that there is a correlation between behavioral improvement and the left cerebellar activation over time, and that there is a shift towards stronger frontal left-lateralization of the fMRI activation over the first year post-stroke. Temporary compensation observed in the initial phases of post-stroke recovery that involves the non-lesioned hemisphere may not be as important as previously postulated, since in this study the recovery was driven by activations in the left fronto-temporal regions. CONCLUSION Language recovery after left hemispheric ischemic stroke is likely driven by the previously involved in language and attention left hemispheric networks.
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Affiliation(s)
- Rodolphe Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jane B Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amber M Martin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Christi Banks
- Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Jennifer Vannest
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Scott K Holland
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kimberly W Hart
- Department of Emergency Medicine, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Christopher J Lindsell
- Department of Emergency Medicine, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.,currently at Department of Biostatistics, Vanderbilt University, Department of Biostatistics, Nashville, TN, USA
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
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Fridriksson J, Elm J, Stark BC, Basilakos A, Rorden C, Sen S, George MS, Gottfried M, Bonilha L. BDNF genotype and tDCS interaction in aphasia treatment. Brain Stimul 2018; 11:1276-1281. [PMID: 30150003 PMCID: PMC6293970 DOI: 10.1016/j.brs.2018.08.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 08/13/2018] [Accepted: 08/14/2018] [Indexed: 12/12/2022] Open
Abstract
Background: Several studies, including a randomized controlled trial by our group, support applying anodal tDCS (A-tDCS) to the left hemisphere during behavioral aphasia treatment to improve outcomes. A clear mechanism explaining A-tDCS’s efficacy has not been established, but modulation of neuroplasticity may be involved. Objective/hypothesis: The brain-derived neurotrophic factor (BDNF) gene influences neuroplasticity and may modulate the effects of tDCS. Utilizing data from our recently completed trial, we conducted a planned test of whether aphasia treatment outcome is influenced by interaction between A-tDCS and a single-nucleotide polymorphism of the BDNF gene, rs6265. Methods: Seventy-four individuals with chronic stroke-induced aphasia completed 15 language therapy sessions and were randomized to receive 1 mA A-tDCS or sham tDCS (S-tDCS) to the intact left temporoparietal region for the first 20 min of each session. BDNF genotype was available for 67 participants: 37 participants had the typical val/val genotype. The remaining 30 participants had atypical BDNF genotype (Met allele carriers). The primary outcome factor was improvement in object naming at 1 week after treatment completion. Maintenance of treatment effects was evaluated at 4 and 24 weeks. Results: An interaction was revealed between tDCS condition and genotype for treatment-related naming improvement (F = 4.97, p = 0.03). Participants with val/val genotype who received A-tDCS showed greater response to aphasia treatment than val/val participants who received S-tDCS, as well as the Met allele carriers, regardless of tDCS condition. Conclusion: Individuals with the val/val BDNF genotype are more likely to benefit from A-tDCS during aphasia treatment.
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Affiliation(s)
- Julius Fridriksson
- Department of Communication Sciences & Disorders, University of South Carolina, USA.
| | - Jordan Elm
- Department of Public Health Sciences, Medical University of South Carolina, USA
| | - Brielle C Stark
- Department of Communication Sciences & Disorders, University of South Carolina, USA
| | - Alexandra Basilakos
- Department of Communication Sciences & Disorders, University of South Carolina, USA
| | - Chris Rorden
- Department of Psychology, University of South Carolina, USA
| | - Souvik Sen
- Department of Neurology, University of South Carolina, USA
| | - Mark S George
- Department of Psychiatry, Medical University of South Carolina, USA; Department of Neurology, Medical University of South Carolina, USA; Ralph H. Johnson VA Medical Center, Charleston, USA
| | - Michelle Gottfried
- Department of Public Health Sciences, Medical University of South Carolina, USA
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, USA
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Szaflarski JP, Griffis J, Vannest J, Allendorfer JB, Nenert R, Amara AW, Sung V, Walker HC, Martin AN, Mark VW, Zhou X. A feasibility study of combined intermittent theta burst stimulation and modified constraint-induced aphasia therapy in chronic post-stroke aphasia. Restor Neurol Neurosci 2018; 36:503-518. [DOI: 10.3233/rnn-180812] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Jerzy P. Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joseph Griffis
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
- Currently at Washington University in St. Louis, St. Louis, MO, USA
| | - Jennifer Vannest
- Cincinnati Children’s Hospital Medical Center, Division of Neurology and Pediatric Neuroimaging Research Consortium, Cincinnati, OH, USA
| | - Jane B. Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rodolphe Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amy W. Amara
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- UAB Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Victor Sung
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Harrison C. Walker
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amber N. Martin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Victor W. Mark
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xiaohua Zhou
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
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